Utilidad de la prueba de la fibronectina fetal y de la longitud del cérvix en la predicción del parto prematuro en gestantes sintomáticas

Objective

To evaluate the usefulness of fetal fibronectin and cervical length in predicting preterm birth in women with preterm uterine contractions.

Material and methods

A prospective study was conducted at the Virgen Macarena Hospital in Seville that included 153 pregnant women with suspected preterm labor and intact membranes. Cervical length was measured by transvaginal sonography and a rapid qualitative fibronectin test was performed in the emergency consultation. Women with a negative fibronectin test and cervical length ≥ 30 mm were not hospitalized or treated with tocolytics or corticosteroids.

Results

The mean gestational age at diagnosis was 223,02 ± 19,98 days, and 267,52 ± 14,15 days at delivery. Preterm birth < 37 weeks rate was 23% and 7,4% for deliveries < 35 weeks. There is an association between cervical length < 30 mm and birth < 37 weeks (OR, 3,68; 95% CI, 1,53-8,84), and with delivery in the following 14 days (OR, 3,35; 95% CI, 1,30-21,95). With the association of both tests we gain specificity in predicting preterm birth.

Conclusion

Cervical length is the test with higher specificity (E) and negative predictive value (VPN) for the prediction of preterm birth in women with symptomatic contractions.